Well, 'A Sign of Affection' manga is popular because it combines romance and drama in a way that's both heartwarming and exciting. The way the story unfolds is captivating and the illustrations are amazing.
A sign of affection novels often focus on the development of a deep emotional connection between the main characters. They might include small gestures, meaningful looks, and shared experiences that build up the romance. Also, the writing style is usually descriptive and evocative, making readers feel the intensity of the affection.